metis wrote:big led..... coudl be fun... inflatable...... can you generate a current from lake water using differing metal leads?

A was noticing that a large part of the shanty we were going to rescue was plastic sheeting, wrap that around a frame add an anode and cathode, light from inside (perhaps with changing colors for the RGB led effect). Would look pretty impressive.

One wrinkle, though--everything has to be cleaned up. No trace left behind, nothing getting dumped in the lake once the ice breaks up. (I was thinking somewhat along these lines too, last meetup.) So whatever we deploy will need to be retrievable, and the easier the better; chipping stuff out of the top layer of ice on teardown day would be miserable.

noise wrote:Probably have to wire them all together and power externally though.

Wait, you want to freeze them in ice AND light them up? That's different.Actually, external power shouldn't be necessary. If you can keep the circuit waterproof somehow, end-to-end, then keeping a battery and a position switch waterproof is no harder. (Lithium batteries, though, since they're not affected by cold the way alkalines are.) A bunch of clear shrink-tubing of various inner diameters would be useful in sealing stuff up, along with hot glue. Then your big block of glowy ice could be turned on, simply by turning it upright; you could put a ball bearing in a tube with contacts at one end for this. You could even use a mercury switch salvaged from an old-style thermostat, if you're careful enough.